What is Geothermal Power Generation?
Transcript of What is Geothermal Power Generation?
What is Geothermal Power Generation?
SSttrruuccttuurree ooff tthhee iinnssiiddee ooff tthhee EEaarrtthh aanndd ggeeootthheerrmmaall ppoowweerr ggeenneerraattiioonn The earth has a three-layer structure consisting of the core, the mantle, and the crust.
The central part of the Earth is said to have a temperature of over 5,000C and is assumed to be a mass of iron, and rocks of mantle melted by the temperature turn into a high temperature liquid called “magma.” When magma reaches Earth’s surface, it erupts and forms a volcano. Below a volcano, there is a “magma chamber” which has a high temperature of around 1,000C regardless of its depth, and it heats surrounding rocks and water and in some cases may form a “geothermal reservoir.” Geothermal power generation makes use of geothermal fluid (steam and hot water) of a geothermal reservoir. CChhaarraacctteerriissttiiccss ooff ggeeootthheerrmmaall ppoowweerr ggeenneerraattiioonn Compared with finite resources (petroleum, coal, etc.), geothermal heat is recyclable energy which can be used permanently if we use it systematically, and it can supply power steadily regardless of weather, time of day, or season. Also, it is characteristic in that CO2 emissions are less than in the case of power generation using petroleum, coal, natural gas, or the like.
For Japan, which relies on imports for most of its energy resources, promoting geothermal power generation leads to saving of fossil fuels, as geothermal resources are abundant in Japan, a country rich in volcanoes, and geothermal power generation is highly expected to make efficient use of regional resources. SSttrruuccttuurree ooff aa ggeeootthheerrmmaall ppllaanntt Geothermal power plant generates electric power by rotating a turbine with steam extracted from a geothermal reservoir.
A well (production well) called a “winze” is dug, and geothermal fluid is taken out from a geothermal reservoir and separated into steam and hot water with a steam separator. The steam rotates a turbine to generate power, and the hot water is returned deep in the ground through an injection well. The steam which has finished its job is cooled with a steam condenser or a cooling tower. SSttrruuccttuurree ooff bbiinnaarryy ppoowweerr ggeenneerraattiioonn When a geothermal fluid has a medium to low temperature, a method called binary power generation is employed: heat of a geothermal fluid is exchanged with that of a medium whose boiling point is lower than water (N pentane, etc.), and a turbine is rotated with steam of the medium. This method very much increases possibilities of geothermal power generation and it is employed in more and more instances year by year.
Earth “Crust”
Surface of the Earth
“Outer core” Iron liquid covering
the inner core
“Mantle” Layer of rock or the like ranging from the crust to
the outer core
“Inner core” Mass of iron located in the
center of the Earth (5,000-6,000C)
Steam and hot water
Hot water
Steam separator
Turbine Generator
Electricity
Power line
Steam condenser
Warm water
Cooling air
Cooling water
Cooling tower
Steam
Prod
uctio
n w
ell
Inje
ctio
n w
ell
Ther
mal
wel
l
Depth of several
hundred meters
Magma chamber
Depth of 1000-
3000 m
Geothermal reservoir
Geothermal water
Medium (gas)
Evaporator
Preheater
Condenser Cooling pump
Cooling tower
Cooling water
Medium feed pump
Medium (liquid)
Geothermal reservoir
Prod
uctio
n w
ell
Inje
ctio
n w
ell
Turbine Generator
Outline of Sugawara Binary Power Station
Sugawara Binary Power Station is one of the geothermal binary power stations with the largest output in the country and it is the third in the country to employ a geothermal binary power generation method over the MW class (as of June 2015).
Among the geothermal binary power stations of the Kyushu Electric Power Company Group, it is the second facility, after Hatchobaru Binary Power Station, which is the first station in the country (Sugawara Binary Power Station is the sixth geothermal power station among the Kyushu Electric Power Company Group).
Also, it is the first geothermal power station operated by the cooperation of a local government and a private enterprise.
Oita Prefecture
SSuuggaawwaarraa BBiinnaarryy PPoowweerr SSttaattiioonn
Outline of Sugawara Binary Power Station Address
Manufacturer of main machine
Rated output
Steam, hot water (outlet of steam
separator)
Medium steam (inlet of turbine)
Generator
Steam separator
Steam condenser
Heat exchangers
Production well
Injection well
Operation management of the power station
Power generation facility main body installation area
Power line system
Commercial operation started in
Owner of the power station/owner of the geothermal well
Pressure/temperature
Steam flow
Hot water flow
Pressure
Temperature
Flow
Working medium
Model
Rotation speed
Type
Maximum working pressure/temperature
Model
Number of fans
Inlet temperature of gas/inlet temperature of medium/outlet temperature
Evaporator
Preheater
Feed liquid heater
Temperature of steam, amount of steam, depth of excavation
Method
554-13 Oaza Sugawara, Kokonoe-machi, Kusu-gun, Oita
Mitsubishi Hitachi Power Systems (TURBODEN (Italy))
Generation end 5,000 kW
N pentane (boiling point: 36C) Horizontal cylindrical rotating field type synchronous generator
Vertical cylinder cyclone separator
Mechanical-draft cooling method
27 units (3 units x 9 rows)
Horizontal straight tube method (1 unit)
Horizontal straight tube method (1 unit)
Horizontal U-shaped tube method (1 unit)
Approx. 47 m x 74 m
Approx. 20 km As-needed monitoring method (remote monitoring is conducted in an on-site monitoring office) June 2015
Kyuden Mirai Energy Company, Incorporated / Local government of Kokonoe-machi
What is Geothermal Power Generation?
SSttrruuccttuurree ooff tthhee iinnssiiddee ooff tthhee EEaarrtthh aanndd ggeeootthheerrmmaall ppoowweerr ggeenneerraattiioonn The earth has a three-layer structure consisting of the core, the mantle, and the crust.
The central part of the Earth is said to have a temperature of over 5,000C and is assumed to be a mass of iron, and rocks of mantle melted by the temperature turn into a high temperature liquid called “magma.” When magma reaches Earth’s surface, it erupts and forms a volcano. Below a volcano, there is a “magma chamber” which has a high temperature of around 1,000C regardless of its depth, and it heats surrounding rocks and water and in some cases may form a “geothermal reservoir.” Geothermal power generation makes use of geothermal fluid (steam and hot water) of a geothermal reservoir. CChhaarraacctteerriissttiiccss ooff ggeeootthheerrmmaall ppoowweerr ggeenneerraattiioonn Compared with finite resources (petroleum, coal, etc.), geothermal heat is recyclable energy which can be used permanently if we use it systematically, and it can supply power steadily regardless of weather, time of day, or season. Also, it is characteristic in that CO2 emissions are less than in the case of power generation using petroleum, coal, natural gas, or the like.
For Japan, which relies on imports for most of its energy resources, promoting geothermal power generation leads to saving of fossil fuels, as geothermal resources are abundant in Japan, a country rich in volcanoes, and geothermal power generation is highly expected to make efficient use of regional resources. SSttrruuccttuurree ooff aa ggeeootthheerrmmaall ppllaanntt Geothermal power plant generates electric power by rotating a turbine with steam extracted from a geothermal reservoir.
A well (production well) called a “winze” is dug, and geothermal fluid is taken out from a geothermal reservoir and separated into steam and hot water with a steam separator. The steam rotates a turbine to generate power, and the hot water is returned deep in the ground through an injection well. The steam which has finished its job is cooled with a steam condenser or a cooling tower. SSttrruuccttuurree ooff bbiinnaarryy ppoowweerr ggeenneerraattiioonn When a geothermal fluid has a medium to low temperature, a method called binary power generation is employed: heat of a geothermal fluid is exchanged with that of a medium whose boiling point is lower than water (N pentane, etc.), and a turbine is rotated with steam of the medium. This method very much increases possibilities of geothermal power generation and it is employed in more and more instances year by year.
Earth “Crust”
Surface of the Earth
“Outer core” Iron liquid covering
the inner core
“Mantle” Layer of rock or the like ranging from the crust to
the outer core
“Inner core” Mass of iron located in the
center of the Earth (5,000-6,000C)
Steam and hot water
Hot water
Steam separator
Turbine Generator
Electricity
Power line
Steam condenser
Warm water
Cooling air
Cooling water
Cooling tower
Steam
Prod
uctio
n w
ell
Inje
ctio
n w
ell
Ther
mal
wel
l
Depth of several
hundred meters
Magma chamber
Depth of 1000-
3000 m
Geothermal reservoir
Geothermal water
Medium (gas)
Evaporator
Preheater
Condenser Cooling pump
Cooling tower
Cooling water
Medium feed pump
Medium (liquid)
Geothermal reservoir
Prod
uctio
n w
ell
Inje
ctio
n w
ell
Turbine Generator
Outline of Sugawara Binary Power Station
Sugawara Binary Power Station is one of the geothermal binary power stations with the largest output in the country and it is the third in the country to employ a geothermal binary power generation method over the MW class (as of June 2015).
Among the geothermal binary power stations of the Kyushu Electric Power Company Group, it is the second facility, after Hatchobaru Binary Power Station, which is the first station in the country (Sugawara Binary Power Station is the sixth geothermal power station among the Kyushu Electric Power Company Group).
Also, it is the first geothermal power station operated by the cooperation of a local government and a private enterprise.
Oita Prefecture
SSuuggaawwaarraa BBiinnaarryy PPoowweerr SSttaattiioonn
Outline of Sugawara Binary Power Station Address
Manufacturer of main machine
Rated output
Steam, hot water (outlet of steam
separator)
Medium steam (inlet of turbine)
Generator
Steam separator
Steam condenser
Heat exchangers
Production well
Injection well
Operation management of the power station
Power generation facility main body installation area
Power line system
Commercial operation started in
Owner of the power station/owner of the geothermal well
Pressure/temperature
Steam flow
Hot water flow
Pressure
Temperature
Flow
Working medium
Model
Rotation speed
Type
Maximum working pressure/temperature
Model
Number of fans
Inlet temperature of gas/inlet temperature of medium/outlet temperature
Evaporator
Preheater
Feed liquid heater
Temperature of steam, amount of steam, depth of excavation
Method
554-13 Oaza Sugawara, Kokonoe-machi, Kusu-gun, Oita
Mitsubishi Hitachi Power Systems (TURBODEN (Italy))
Generation end 5,000 kW
N pentane (boiling point: 36C) Horizontal cylindrical rotating field type synchronous generator
Vertical cylinder cyclone separator
Mechanical-draft cooling method
27 units (3 units x 9 rows)
Horizontal straight tube method (1 unit)
Horizontal straight tube method (1 unit)
Horizontal U-shaped tube method (1 unit)
Approx. 47 m x 74 m
Approx. 20 km As-needed monitoring method (remote monitoring is conducted in an on-site monitoring office) June 2015
Kyuden Mirai Energy Company, Incorporated / Local government of Kokonoe-machi
Structure of Sugawara Binary Power Generation
Sugawara Binary Power Station employs a “binary power generation” method which heats and evaporates a fluid whose boiling point is lower than that of water (medium: N pentane) with a geothermal fluid supplied from the production wells and rotates the turbine with medium steam. Also, a geothermal fluid serving as a heat source is supplied from a well owned by Kokonoe-machi, and N pentane is cooled and liquefied by the air cooling method.
Silencer Steam
conveying pipe
Evaporator
Main transformer
Condensed water pump
To factories, buildings, stores, and general
houses
Generator
Cooling air
Two-phase fluid (geothermal steam, hot water) system
Geothermal steam system
Geothermal hot water system
N pentane system
Flow of electricity
Con
dens
ed
wat
er ta
nk
Steam turbine
Hot water conveying
pipe
Hot water tank
Two-
phas
e flu
id
conv
eyin
g pi
pe
Production well Injection
well
Medium pump
Steam condenser (Air cooling
method)
Steam separator
Preheater
Geothermal reservoir
Production well It is a well for extracting high-temperature steam and hot water from the geothermal reservoir located deep in the ground. Steam and hot water are sent to the steam separator via the two-phase fluid conveying pipe.
Two-phase fluid conveying pipe
Steam separator
It is a pipe for sending to the steam separator steam and hot water extracted from the production wells in a mixed state (two-phase state). Instead of conducting separation near the mine mouth, steam and hot water from the winzes are gathered and conveyed in the two-phase state. This improves the efficiency of fluid transportation.
It is equipment for separating the two-phase fluid extracted from the production wells, which is a mixture of steam and hot water, into steam and hot water. After separation, steam is subjected to heat exchange in the evaporator while hot water is subjected to the same in the preheater, and then they are returned underground through the injection well.
Evaporator
It is equipment for heating N pentane with geothermal steam to evaporate it. Evaporated N pentane is sent to the turbine to rotate the generator in order to generate electricity.
Meanwhile, geothermal steam turns back into liquid and is sent to the condensed water tank.
High temperature and high pressure N pentane (gas) which has been sent from the evaporator rotates the turbine about 3,000 rotations per minute. The turbine rotates the generator, which is connected to the turbine, via a reducer to generate electricity. N pentane used in the turbine is sent to the steam condenser.
Turbine, generator
Preheater
It is equipment to preheat N pentane which has been cooled by the steam condenser with hot water and condensed water before it is sent through the evaporator. Meanwhile, hot water and condensed water which have been cooled by passing through the preheater are sent to the injection well.
It is a tank for storing condensed water obtained by turning geothermal steam back into liquid by transferring heat with the evaporator. After that, the condensed water is sent to the preheater and used for preheating N pentane.
Condensed water tank
It is a facility to cool and liquefy N pentane (gas) used in the turbine with air from the outside. Liquefied N pentane is heated again with the preheater and evaporator, turns into a high temperature gas, and then, is sent to the turbine again.
Steam condenser (Air cooling method)
It is a well for returning condensed water which has been turned back into a liquid by exchanging heat with hot water extracted from the production wells and the evaporator to the underground. In principle, all high temperature steam and hot water extracted from the production wells is returned underground by using only their heat. The system is therefore environmentally friendly.
Injection well
Structure of Sugawara Binary Power Generation
Sugawara Binary Power Station employs a “binary power generation” method which heats and evaporates a fluid whose boiling point is lower than that of water (medium: N pentane) with a geothermal fluid supplied from the production wells and rotates the turbine with medium steam. Also, a geothermal fluid serving as a heat source is supplied from a well owned by Kokonoe-machi, and N pentane is cooled and liquefied by the air cooling method.
Silencer Steam
conveying pipe
Evaporator
Main transformer
Condensed water pump
To factories, buildings, stores, and general
houses
Generator
Cooling air
Two-phase fluid (geothermal steam, hot water) system
Geothermal steam system
Geothermal hot water system
N pentane system
Flow of electricity
Con
dens
ed
wat
er ta
nk
Steam turbine
Hot water conveying
pipe
Hot water tank
Two-
phas
e flu
id
conv
eyin
g pi
pe
Production well Injection
well
Medium pump
Steam condenser (Air cooling
method)
Steam separator
Preheater
Geothermal reservoir
Production well It is a well for extracting high-temperature steam and hot water from the geothermal reservoir located deep in the ground. Steam and hot water are sent to the steam separator via the two-phase fluid conveying pipe.
Two-phase fluid conveying pipe
Steam separator
It is a pipe for sending to the steam separator steam and hot water extracted from the production wells in a mixed state (two-phase state). Instead of conducting separation near the mine mouth, steam and hot water from the winzes are gathered and conveyed in the two-phase state. This improves the efficiency of fluid transportation.
It is equipment for separating the two-phase fluid extracted from the production wells, which is a mixture of steam and hot water, into steam and hot water. After separation, steam is subjected to heat exchange in the evaporator while hot water is subjected to the same in the preheater, and then they are returned underground through the injection well.
Evaporator
It is equipment for heating N pentane with geothermal steam to evaporate it. Evaporated N pentane is sent to the turbine to rotate the generator in order to generate electricity.
Meanwhile, geothermal steam turns back into liquid and is sent to the condensed water tank.
High temperature and high pressure N pentane (gas) which has been sent from the evaporator rotates the turbine about 3,000 rotations per minute. The turbine rotates the generator, which is connected to the turbine, via a reducer to generate electricity. N pentane used in the turbine is sent to the steam condenser.
Turbine, generator
Preheater
It is equipment to preheat N pentane which has been cooled by the steam condenser with hot water and condensed water before it is sent through the evaporator. Meanwhile, hot water and condensed water which have been cooled by passing through the preheater are sent to the injection well.
It is a tank for storing condensed water obtained by turning geothermal steam back into liquid by transferring heat with the evaporator. After that, the condensed water is sent to the preheater and used for preheating N pentane.
Condensed water tank
It is a facility to cool and liquefy N pentane (gas) used in the turbine with air from the outside. Liquefied N pentane is heated again with the preheater and evaporator, turns into a high temperature gas, and then, is sent to the turbine again.
Steam condenser (Air cooling method)
It is a well for returning condensed water which has been turned back into a liquid by exchanging heat with hot water extracted from the production wells and the evaporator to the underground. In principle, all high temperature steam and hot water extracted from the production wells is returned underground by using only their heat. The system is therefore environmentally friendly.
Injection well
Background to Starting the Operation of Sugawara Binary Power Station
The period between the planning and the operation start was reduced because Sugawara Binary Power Station was of middle scale and did not require newly excavating a production well or the like, and the development was promoted by cooperation of the local government.
1. Ground surface investigation
New Energy and Industrial Technology Development Organization (NEDO) excavated three geothermal wells in Kokonoe-machi for demonstration experiment of geothermal study.
2. Underground prospecting and evaluation
NEDO transferred the wells to Kokonoe-machi free of charge.
Kokonoe-machi conferred with Kyushu Electric Power Co., Inc. about geothermal development. Effective utilization of the geothermal wells owned by the town was studied.
End of May – December Well discharge test started (about 3 months) In addition, investigation on impacts on surrounding hot springs was carried out.
3. Discussion with the local community 4. Construction 5. Operation
November 22 Kokonoe-machi, Kyushu Electric Power Co., Inc. and Nishinippon Environmental Energy Co., Inc. concluded the “Basic Agreement on Geothermal Power Generation Project in Sugawara Area” in the presence of the Governor of Oita Prefecture.
March 27 The project was one of the first two cases to be adopted as a case in which geothermal resources development debt is guaranteed by the Japan Oil, Gas and Metals National Corporation (JOGMEC). (Sugawara, Kokonoe-machi, and Tsuchiya Hot Spring, Fukushima) April 10 Groundbreaking ceremony was conducted April 21 Nishinippon Environmental Energy started the construction July 1 The construction was transferred in association with the establishment of Kyuden Mirai Energy
April 1 (reception of power) – June 29 Test operation June 29 Operation started
* Provided by Oita Prefecture
First Geothermal Power Generation Project in the Country Worked in Collaboration with a Local Government
The Sugawara Binary Power Generation Project is a geothermal power generation project on which we work together with Kokonoe-machi local government.
Kokonoe-machi provides us with steam and hot water from their geothermal wells and we generate electricity by using the geothermal binary power station established and operated by us.
We sell generated electricity to Kyushu Electric Power Co., Inc., and we pay heat usage fee to Kokonoe-machi with income obtained by selling electricity. Both we and Kokonoe-machi can make a steady income while simultaneously contributing to effective use of purely domestic energy and promotion of global warming prevention.
We also make efforts to coexist with the local communities by, for example, implementing a hot spring monitoring with the cooperation of Kokonoe-machi, giving explanations to the local communities, etc.
Pays fee for using steam heat
Miya-chan, Kokonoe-machi
Kokonoe- machi Provides
steam and hot water
Sugawara Binary Power Station
Income on selling electricity
All electricity is sold under a feed-in tariff
(FIT) system
Kyushu Electric Power Co., Inc.
Corporate profile
Business lineup
Business area
Establishment
Capital
Representative
Employees
Stockholder
Affiliate company
Recyclable energy power generation service (geothermal, wind power, biomass, hydropower, solar power) Retail electricity service(*)
Inside and outside the country
July 1, 2014
669.55 million yen
Yasuji Akiyama, President
120 (as of April 1, 2016)
Kyushu Electric Power Co., Inc. 100%
Miyazaki Biomass Recycle Co., Inc., Nagashima Windhill Co., Inc., Kushima Windhill Co., Inc.
(*) Since April 2016, sales of electricity has been started in Kanto Area.
[Contact] Kyuden Mirai Energy Company, Incorporated
3F Shogakukan Building, 2-4-8 Watanabe –dori, Chuo-ku, Fukuoka-shi, Fukuoka, 810-0004
(9 am – 5 pm, excluding Saturdays, Sundays, and national holidays)
Background to Starting the Operation of Sugawara Binary Power Station
The period between the planning and the operation start was reduced because Sugawara Binary Power Station was of middle scale and did not require newly excavating a production well or the like, and the development was promoted by cooperation of the local government.
1. Ground surface investigation
New Energy and Industrial Technology Development Organization (NEDO) excavated three geothermal wells in Kokonoe-machi for demonstration experiment of geothermal study.
2. Underground prospecting and evaluation
NEDO transferred the wells to Kokonoe-machi free of charge.
Kokonoe-machi conferred with Kyushu Electric Power Co., Inc. about geothermal development. Effective utilization of the geothermal wells owned by the town was studied.
End of May – December Well discharge test started (about 3 months) In addition, investigation on impacts on surrounding hot springs was carried out.
3. Discussion with the local community 4. Construction 5. Operation
November 22 Kokonoe-machi, Kyushu Electric Power Co., Inc. and Nishinippon Environmental Energy Co., Inc. concluded the “Basic Agreement on Geothermal Power Generation Project in Sugawara Area” in the presence of the Governor of Oita Prefecture.
March 27 The project was one of the first two cases to be adopted as a case in which geothermal resources development debt is guaranteed by the Japan Oil, Gas and Metals National Corporation (JOGMEC). (Sugawara, Kokonoe-machi, and Tsuchiya Hot Spring, Fukushima) April 10 Groundbreaking ceremony was conducted April 21 Nishinippon Environmental Energy started the construction July 1 The construction was transferred in association with the establishment of Kyuden Mirai Energy
April 1 (reception of power) – June 29 Test operation June 29 Operation started
* Provided by Oita Prefecture
First Geothermal Power Generation Project in the Country Worked in Collaboration with a Local Government
The Sugawara Binary Power Generation Project is a geothermal power generation project on which we work together with Kokonoe-machi local government.
Kokonoe-machi provides us with steam and hot water from their geothermal wells and we generate electricity by using the geothermal binary power station established and operated by us.
We sell generated electricity to Kyushu Electric Power Co., Inc., and we pay heat usage fee to Kokonoe-machi with income obtained by selling electricity. Both we and Kokonoe-machi can make a steady income while simultaneously contributing to effective use of purely domestic energy and promotion of global warming prevention.
We also make efforts to coexist with the local communities by, for example, implementing a hot spring monitoring with the cooperation of Kokonoe-machi, giving explanations to the local communities, etc.
Pays fee for using steam heat
Miya-chan, Kokonoe-machi
Kokonoe- machi Provides
steam and hot water
Sugawara Binary Power Station
Income on selling electricity
All electricity is sold under a feed-in tariff
(FIT) system
Kyushu Electric Power Co., Inc.
Corporate profile
Business lineup
Business area
Establishment
Capital
Representative
Employees
Stockholder
Affiliate company
Recyclable energy power generation service (geothermal, wind power, biomass, hydropower, solar power) Retail electricity service(*)
Inside and outside the country
July 1, 2014
669.55 million yen
Yasuji Akiyama, President
120 (as of April 1, 2016)
Kyushu Electric Power Co., Inc. 100%
Miyazaki Biomass Recycle Co., Inc., Nagashima Windhill Co., Inc., Kushima Windhill Co., Inc.
(*) Since April 2016, sales of electricity has been started in Kanto Area.
[Contact] Kyuden Mirai Energy Company, Incorporated
3F Shogakukan Building, 2-4-8 Watanabe –dori, Chuo-ku, Fukuoka-shi, Fukuoka, 810-0004
(9 am – 5 pm, excluding Saturdays, Sundays, and national holidays)